(This Old House) -- A few years ago, marketing executive and green thumb David Jensen of Clare, Michigan, moved outside the city limits so he could grow a bigger, better garden -- only to watch it get devoured by deer that seemed to fear nothing.

Eventually, he quit his job and opened the Deer Resistant Landscape Nursery, which specializes in plants and products that limit the extent of the damage.

The population of deer is at an all-time high -- "more now than when the Pilgrims landed," says Michael Conover, a professor of wildlife at Utah State University. He cites the decline of hunting as a major reason that deer are encroaching onto residential lots: "Deer have lost their fear of man, basically."

Handsome as they are, deer destroy expensive plantings, carry ticks that spread Lyme disease and cause more than a half-million auto collisions each year. Unfortunately, some of their favorite snacks are common landscape plants, including roses, tulips, hostas, many ornamental shrubs such as rhododendron and yew, to say nothing of leafy vegetable gardens.

Deer are intelligent and highly adaptable creatures; when they get hungry enough, they'll test the limits of just about any preventive measure. That's why experts recommend an "integrated management plan" -- that is, using a variety of techniques.

"You have to keep them guessing," says This Old House landscape contractor Roger Cook, a veteran of the deer wars. "I always recommend rotating repellents and combining them with scare tactics and fencing."

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Among the most foolproof deterrents are physical barriers like fences. Deer are agile jumpers, so fences need to be high -- typically about 8 feet. Black propylene deer fencing in a 2-inch net ($2 to $4 per foot) is virtually invisible in a wooded setting and relatively easy to install; metal sleeves are pounded into the ground every 15 feet, and thin metal posts are inserted in the sleeves. The netting is clipped to the posts, then stretched tight. This Old House: Step-by-step picket fence

Spray them away

Spritzing on liquids with an offensive odor or taste is the least expensive way to repel them -- with varying degrees of success. Commercial products like Deer-Off (based on eggs, hot peppers, and garlic) or Plantskydd (a blood-meal solution) are sprayed directly on plants to render them unpalatable. Other products contain predator scents like coyote urine that can be deposited strategically around the yard.

Some gardeners swear by odiferous homebrews made from ingredients like rotten eggs, chili powder, and scented soaps. Any spray -- commercial or homemade -- needs to be reapplied frequently as plants grow or rain washes it away.

Scare them off

Often deer can be kept at bay with scare tactics, usually a surprise burst of water or a loud noise. One popular product is the Scarecrow ($89; contech-inc.com), which combines a motion detector and a sprinkler that sprays water when deer (or other critters) cross its path.

Placement is everything with such products, and hungry deer may eventually learn to ignore them. Some homeowners find that a vigilant dog is the best scare tactic, since canine predators like coyotes and wolves are deer's natural enemies. This Old House: Classic American doghouses

Plant their least-favorite foods

Experts agree that overall, the best defense is a good offense -- landscaping around your home with plants that are not to deer's liking. "Many plants have their own repellent built in," says Jensen. Deer will usually turn away from highly aromatic or poisonous plants (such as foxglove), and those with fuzzy leaves.